The invention relates to a gas bag module.
There are known gas bag modules which have a gas generator and a rigid housing in which the gas generator is arranged. The housing may have at least two gas outflow channels for distributing the inflation gas to the chambers of the gas bag.
Gas bags, especially those for protecting vehicle occupants from lateral impact, are being increasingly divided into several chambers. Partly, these chambers are of differing size, but partly also the requirement is set that the chambers are to have differing internal pressures. For this, it is necessary to specifically introduce the gas emerging from the gas generator of the gas bag module into the individual chambers of the gas bag.
It is an object of the invention to ensure such a defined gas distribution.
According to the invention, a gas bag module comprises a gas generator and a rigid housing in which the gas generator is arranged. The housing has at least two gas outflow channels with one port each, the ports adjoining each other and being directed towards the gas generator and separated from each other by a wall. The gas generator has a continuous gas outflow zone with at least two sections, each of the sections of the gas outflow zone being associated with one of the ports. The housing is constructed such that gas emerging from the sections of the gas outflow zone can only flow into the one of the gas outflow channels which is associated with the respective section. In other words, the gas emerging from the gas generator is distributed to gas outflow channels by means of the housing surrounding the gas generator, and directly on the emerging of the gas. These gas outflow channels can then direct the gas into the respective specific chambers of a gas bag, for example. As the gas is directly led off after it has emerged, a high pressure-induced stress of the housing is avoided.
Preferably, the wall which separates the ports from each other lies against the gas generator, in order to separate the two channel ports from each other with respect to flow.
It is particularly favorable if the wall is a rib constructed on the housing. In this case, through the construction of the housing, in particular through the positioning of the rib, a specific gas distribution can be established. For this purpose, it is particularly advantageous if the housing is a one-piece housing made of plastics, preferably an injection-molded part. This construction makes it possible to carry out an adaptation of the gas distribution to various applications, for example for differing gas bags for various types of vehicle, solely through the shape of the housing. Advantageously the same type of gas generator can be used for all the different purposes of application.
The quantity of gas flowing out from the gas generator may also be distributed to the channels in a simple manner in proportions of differing amounts by the channels being constructed and arranged accordingly. For this, the wall which separates the ports of the channels from each other merely has to be positioned in the housing at an appropriate site of the gas outflow zone. As the gas flows directly from the gas generator into the channels, there is no interfering influence on the gas outflow by the emerging gas. Thus, a ratio of the proportions of greater than 60:40 can be achieved in a simple manner.
The connected gas outflow zone may have a plurality of outflow openings, which are constructed for example as rows of holes in the wall of a filter tube of the gas generator. Of course, it is also possible for the gas generator to have several outflow zones, separated from each other spatially and respectively connected for their part. In this case, provision can be made that only one of the outflow zones is active, whilst the other(s) is/are closed, for example by projections which are formed on the housing or on a separate seal and which close the respective outflow openings. Assuming that there are one or more further gas outflow zones separated from the first connected gas outflow zone; then it is possible, of course, that associated with these gas outflow zone(s) are channels which again are separated from each other spatially and with respect to flow by a wall, which channels in turn carry gas away from the gas generator for specific purposes of application. For the invention, it is merely essential that the gas which flows out from the respective section of an outflow zone associated with a channel, can only arrive into this channel.
In an embodiment of the invention, the gas generator is a tubular gas generator, and the gas outflow zone preferably extends only across part of the circumference of the gas generator. With this arrangement, it is particularly simple to place the ports of the channels and the wall lying between them.
The gas bag module is preferably a side gas bag module, in which the gas generator is arranged approximately in the center of the longitudinal extent of the side gas bag, and in which the channels constructed in the housing introduce the gas in chambers of the gas bag without long feed lines.
Further features and advantages of the invention will be apparent from the subclaims as well as the following description of several embodiments.